Unreal Engine Issues
Unreal Engine Issues
Mutable Chaos Cloth breaks when culling mesh affects mesh sections with cloth
UE - Runtime - Mutable - Sep 29, 2026Encountering an issue since we updated to UE5.8 where characters whose cloth mesh sections have vertices culled will cause mesh degradation in editor and crashes in packaged builds. There are two i ...
Light Function and Post Process domain material thumbnails show the default material
UE - Rendering - Architecture - Materials - Sep 25, 2026Since 5.8, materials whose Material Domain is Light Function or Post Process no longer preview correctly in the editor. They render as the default material (WorldGridMaterial) instead of the materia ...
Widget animations queued before Slate creation are not carried out in UE5.8
UE - ACT Character - Sequencer - Sep 24, 2026We are currently upgrading some of our systems from Unreal 5.6 to Unreal 5.8, and we've noticed an issue with Widget animations. In one of our commonly used actors, a Widget animation is queued in t ...
FZipArchiveCompressTest failing to compile in non-editor Development builds
UE - ACT Character - MetaHuman Creator - Jul 28, 2026`ZipArchiveTest.cpp` fails to compile for non-editor targets in Development configuration. `FZipArchiveCompressTest::RunTest` constructs `FZipArchiveReader`, which is editor only, but that section ...
[CrashReport][Crash] Engine!FSceneViewport::UpdateViewportRHI() [SceneViewport.cpp]
UE - Rendering - RHI - May 29, 2026#200 crash out of 2101 in UE 5.8 on Windows#34 crash for UE - Rendering - Architecture in UE 5.8 on Windows#20 crash for UE - Rendering - Architecture - RHI in UE 5.8 on WindowsAssertion failed: IsI ...
The editor crashes to Assertion Failed after enabling a light's "Lighting Channels" from the "Light Mixer" panel
UE - CAPT - Tools - Feb 9, 2026The crash only occurs when enabling the channels of lights that are part of the "BP_SphereLight" or "SM_CubeLight". Enabling the channels of a single "PointLight" or "SpotLight" doesn't crash the ed ...